Various types of high density storage systems have heretofore been known and used in the prior art wherein a plurality of individual storage units are movable in a manner so as to provide for convenient access to the various storage sections, yet minimize to the extreme the space requirements for the overall system. Typically such storage systems consist of rows of storage sections, for example, sections of storage shelves, which are supported upon a common base and movable by means of suitable rollers or the like upon two or more spaced parallel tracks. The length of the tracks is typically approximately equal to the total dimension of the various storage units when placed directly adjacent one another plus the width of an access aisleway along which a person can have access to the shelf sections. Such prior art storage arrangements are shown, for example, in U.S. Pat. Nos. 2,166,704; 2,547,368; 2,915,195; 3,080,204; 3,168,361; 3,427,085; 3,535,009; 3,566,802; 3,575,479 3,640,595; 3,724,389; 3,801,176; and 3,829,189.
While the various patents noted above disclose storage systems which are analogous to the present invention, such prior art structures have been subject to the objectionable criticism in that they have used relatively rigid track elements which necessitated extremely accurate leveling in order to provide for reasonably effortless movement of the storage units. Such leveling has required that the tracks be mounted directly upon an extremely level support surface or floor, or that some means be provided interjacent the surface of an irregular floor and the tracks to assure for accurate leveling thereof. It has been found that even small variations in out of levelness of the tracks results in a significant increase in the effort required to move the storage units therealong. Consequently, significant time and effort has been required to assure for track levelness in order to provide for efficient operation of the prior art storage systems. This, of course, results in an objectionable decrease in the economies of production, installation, maintenance, etc.
The present invention is directed toward a new and improved storage system which is generally related to the systems shown in the aforesaid prior art patents; however, the storage system of the present invention is intended to overcome the objectionable criticism of similar type units in the prior art. In particular, the storage system of the present invention contemplates the use of relatively flexible, as opposed to rigid, tracks which are intended to be mounted directly upon and conform to their respective supporting surfaces over the entire length of any given application, regardless of whether or not such supporting surface may have irregularities therein. By virtue of the compliant nature of the track design, such tracks may be laid on virtually any type of support surface that is normally encountered in application sites without requiring ancillary anchoring means, leveling or otherwise modifying the supporting surfaces. In addition to the above, the storage system of the present invention is developed on a modular unit concept. That is, each of the storage units consists of two or more storage sections, with each of the sections being carried on an individual base. The various sections of each unit are interconnected in a manner so as to provide for relatively limited movement or articulation between the sections and the respective bases thereof so that even though a particular storage unit is designed to move as a single entity, the fact that each storage section of the unit is carried on a complete and non-dependent movable base allows considerable freedom in application while insuring acceptable and predictable performance levels. Thus, as a storage unit is moved, the individual bases act independently with their mating tracks and are not influenced by the adjacent or related tracks. The particular design of the tracks in the storage system of the present invention is such that the wheels or rollers of each of the track section bases are held in positive relationship to one another. Toward this end, the track design provides a V-groove that allows only line contact between the wheel tread edges and the track surface, as well as providing restriction and/or limitation to the rolling path by virtue of the inclined surfaces of the converging sides of the V-shaped grooves within which the wheels traverse. In addition, the wheels of each of the storage section bases are allowed to "float" on their respective axles, whereby to insure optimum wheel to track alignment, as will hereinafter be described in detail.